Swamp

Festering Newt

When Festering Newt dies, target creature an opponent controls gets -1/-1 until end of turn. That creature gets -4/-4 instead if you control a creature named Bogbrew Witch.

Tragic Slip

Target creature gets -1/-1 until end of turn.
Morbid — That creature gets -13/-13 until end of turn instead if a creature died this turn.

Bubbling Cauldron

{1}, {T}, Sacrifice a creature: You gain 4 life.
{1}, {T}, Sacrifice a creature named Festering Newt: Each opponent loses 4 life. You gain life equal to the life lost this way.

Bogbrew Witch

{2}, {T}: Search your library for a card named Festering Newt or Bubbling Cauldron, put it onto the battlefield tapped, then shuffle.